STOCKHOLM — It was a gray summer’s day, but on the first floor of a grand office block typically occupied by bankers and shipping brokers, Matilda Djerf was basking in the glory of Midsommar.

Ms. Djerf, a 25-year-old social media influencer who founded the fashion brand Djerf Avenue with her boyfriend, Rasmus Johansson, in 2019, has forged a fast-growing business empire on tantalizing glimpses of her soft-focus Scandi dream life — not to mention one of TikTok’s most emulated haircuts. But last month, while in her immaculate headquarters, all whitewashed walls and blond floors, there wasn’t a flower crown or embroidered frock in sight. Instead, she watched footage of a group of girls nearly 6,000 miles away, in California, who had thrown a party themed around the traditional Swedish celebration of the summer solstice in her honor.

“We try to be more than a fashion brand,” said Ms. Djerf (pronounced gerf). “We are just as focused on building a community.”

Tanned with rosebud lips and a ski-jump nose, she wore diamond hoop earrings that bounced against her shaggy bangs as she gestured to the screen. “We communicate with customers constantly on social media,” she said. “Many of them find new friends through Djerf Avenue as well as new clothes.”

Ms. Djerf flicked through shots that would later be uploaded to the brand’s Instagram account. The girls, in a range of shapes, sizes and skin tones, beamed in sellout styles like the Dream Dress ($199) or Tie Tank Tops ($119). Nearby, Djerf Avenue employees, identically dressed in oversize poplin shirts and loosely tailored black slacks that mirrored Ms. Djerf’s masculine-meets-feminine style, tapped away on laptops.

“A lot of customers apply to be models,” Ms. Djerf said. “They are so loyal and so devoted. We call them our Djerf Angels. They love to be part of our world.”

Or, more specifically, Matilda Djerf’s world. By buying her clothes and emulating her lifestyle, a growing number of customers believe they can be like Ms. Djerf.

Not that the extent of Ms. Djerf’s influence can fully be gleaned from a list of easily digested numbers. She commands a following of 2.6 million on Instagram and a million on TikTok on her personal accounts. Those are sizable social media metrics, but a far cry from those of American peers such as Addison Rae or Charli D’Amelio. She doesn’t post often. Nor is she the first influencer to create her own brand. What sets Ms. Djerf apart is the devotion she engenders in her fans — and the way she and Mr. Johansson, the chief executive of Djerf Avenue, have leveraged her popularity to build a profitable business with expected sales revenues of $22 million this year, up from $8 million in 2021.

One can scroll through tens of thousands of adoring posts parroting her clothes, her poses, her blow-dry. Among the captions: “girls don’t want boys, they want Matilda Djerf’s hair”; “the feminine urge to be obsessed with Matilda Djerf”; and Matilda Djerf, “the icon of our generation.” Her name has been used as a hashtag on TikTok 156 million times, and she regularly emerges as a face of wider Gen Z fashion trends like “cottagecore,” “coastal grandmother” and “clean girl.” Even though she is not exactly any of those things.

“Matilda Djerf has this very tailored brand and aesthetic that still feels candid and relatable,” said Chelsea Davignon, a senior strategist focused on youth trends at the forecasting agency Fashion Snoops, who praised Ms. Djerf’s ability to master “the formula” across generations and platforms. “She doesn’t flood her feed with other brands or sponsored content. Instead, she offers an effortlessly cool lifestyle that doesn’t feel too out of reach.”

Especially for women who don’t look like her.

Only Just Out of Reach

Ms. Djerf grew up about 250 miles southwest of Stockholm in a small town called Boras, though she speaks perfect English with an American twang thanks to two years in Monterey, Calif., as a child. She and Mr. Johansson are high school sweethearts, and after graduating in 2016, they went backpacking in the Caribbean, Bali and Australia. Ms. Djerf did some modeling for local fashion and bikini brands to pay their way. She also started taking photographs of their travels — and Mr. Johansson took photos of her — which she would then post on her fledgling Instagram account.

By the time they returned to Sweden in 2017, she had 100,000 followers.

“I took a job at a juice store in Boras, but I also realized that maybe, just maybe, we could make a living from social media,” Ms. Djerf said, stressing that she had been a keen photographer and fashion obsessive since childhood. “We were nervous, of course. We’d been in a tropical paradise, and now we’re back in a small town in Sweden. Would anyone care? Was it going to work?”

It did. Girls around the world were fascinated by her, swooning at snapshots of a life eating strawberries or biking in the Swedish countryside in an oversize shirt and bikini; of satin slips, espresso martinis and bouncy blond hair on winter nights out; of her penchant for baggy tailoring with cropped tops that marries Gen Z swagger with a more polished, elegant European “it girl” aesthetic.

By 2019, Ms. Djerf realized she didn’t want to do brand partnerships or collaborations; she wanted her own brand, period. That December, Djerf Avenue released an initial drop of nine pieces that Ms. Djerf felt were missing from her own wardrobe. It sold out overnight.

Now, two and a half years on, Djerf Avenue produces about 10 drops a year, with a logistics warehouse opening in the United States this fall to better cater to its largest market. There are no sales or discounts. Ninety percent of the company is jointly owned by Ms. Djerf and Mr. Johansson, though they sold a 10 percent stake to an angel investor in April — “an airbag,” Ms. Djerf joked as she surveyed a row of freshly steamed designs that required her sign-off.

“What I wanted with Djerf Avenue was to give people classic and comfortable staples that they can wear again and again or style in multiple ways over years,” she said, pointing to an oversize caramel trench and matching stretch tube skirt and top. Sizes for the collections range from XXS to XXXL.

“What was even more important to me was that this was a fashion brand that was completely welcoming and inclusive of everyone” Ms. Djerf said. “That was always my real dream.”

Under the democratizing forces of social media, the range of skin tones, dress sizes and backgrounds celebrated by the news media has expanded considerably in recent years. Ms. Djerf, of course, is the embodiment of the expensive-looking, blond-haired, blue-eyed girl-next-door aesthetic that has long dominated conventional fashion and beauty standards. She may have created a lifestyle blueprint around herself that can be commercialized for a diverse audience, and a platform through which like-minded women can interact with one another, but the face of Djerf Avenue, the reason they come, is ultimately her. It isn’t cheap to be part of her dream, either.

“I am not oblivious to the fact that I am in many ways society’s ideal of what a perfect person looks like,” Ms. Djerf said. “I realize how much privilege I have. I’m white, I’m a small size, I tan easily, I don’t need to wear makeup. That life can be easier for me because of those things. But that doesn’t mean I don’t feel a strong sense of responsibility to do things the right way.”

That sense of obligation is part of the reason that she does not attend fashion weeks in places like Paris or Milan. “It isn’t that I haven’t been invited,” said Ms. Djerf, who believes luxury brands need to get better at sizing and model representation, airbrushing and doctoring images. “But I do think hard about what I support. Do I want to be at a catwalk show and see only size 00s walk the runway? Not really. Nor would it send the right message to the people who are influenced by me. I think about that a lot.”

Finding a Balance

Ms. Djerf’s office is full of soft, cloudlike furniture and vases of pastel-colored wildflowers and hydrangeas. Her dog, Rufus, a mainstay of her posts, chased a ball along rows of vintage kitten heels and down the hall, where an installation hung that looked like a giant, gleaming ring light.

“That’s not what that is supposed to be,” Ms. Djerf said, wrinkling her nose. “I think I like it less now that you’ve said that.”

Behind her, pinned to her mood boards, were letters from fans, every one including the author’s social media handle. “Thank you for creating a fun and safe space for so many people. Plus incredible clothes,” read one. “I love how you are a fierce advocate for self love. It makes me want to be a bit more fierce and love myself a bit more too,” read another. Many of those who post to and about her online have a clear goal in mind: a response from their idol herself.

Ms. Djerf said she spends roughly 11 hours a day working on Djerf Avenue, then an additional hour creating content, and another hour or so replying to messages from her followers. Her IRL social life, for now, has taken something of a back seat.

“I’m probably not a particularly good girlfriend,” she said.

There is no blueprint on how to do her role. She tries, she said, to make the world feel more comfortable and supportive. Sometimes that means offering reminders that what you look like doesn’t equate to happiness. She has spoken about her battle with orthorexia and anorexia as a teenager and an ectopic pregnancy that resulted in emergency surgery in 2020.

“I’ve never spoken about those moments in my life for likes or comments,” she said. “I do it to help raise awareness and so people feel less alone.” That isn’t always an easy thing to balance with her life offline.

“I have a 14-hour day, and then someone really opens up to me because I have built something for them here,” she said. “That is a blessing, truly. But sometimes, many times, I need to find a way to say to them that they need to find help somewhere else, possibly professional help. Sometimes I get very overwhelmed.”

Ms. Djerf said she hasn’t changed how she looks since 2017. And given the online infatuation with her hair — #MatildaDjerfHair has 27 million views on TikTok — she definitely can’t get it cut. Ms. Djerf, who still goes back to her hometown hairdresser for trims, gets a torrent of messages anytime her fluffy Farrah Fawcett-like fringe even remotely starts to drift past her cheekbones. TikTok, which loves a classic hairstyle revival, has classed the look “Bangs With Benefits” and “Butterfly Hair.”

“I get so many compliments and connections from all over the world from my hair, which is so nice,” Ms. Djerf said. “But sometimes messages will be something else, which can make me feel bad. They’ll say: ‘Oh my God. I cut my bangs just like you. And it does not look the same at all.’”